1. Field of the Invention
This patent relates to packaging for large products such as washers, dryers and refrigerators. More particularly, this patent relates to a tubular-type package support post in which adjacent surfaces are joined to prevent slippage between the surfaces so that the post is stiffened along both axial and lateral directions.
2. Description of the Related Art
Package support posts such as corner posts or wall posts consisting essentially of wound paper tubes are used to support and cushion large, heavy appliances (such as washers, dryers, refrigerators, dishwashers and stoves) during storage and transport. Conventional tubular-type support posts are made of a single sheet of paper wound into a convolute (coiled) tube. Adhesive is often used to bond the paper layers. Before the adhesive dries, the tube is shaped into the desired shape. In the case of a corner post, the desired shape typically has a modified "L" shaped cross section to fit snugly about the corner of an appliance or other product.
U.S. Pat. No. 4,482,054, issued to Gardner, discloses one such corner post having longitudinally-extending grooves or indentations to provide improved resistance to longitudinally directed compression forces and enhanced cushioning against laterally directed forces. Indentations on opposing walls are aligned so as to contact each other, thereby defining cylinders separated by the contact areas. The opposing walls are not adhered or bonded to each other at the contact areas. As a result, the exertion of forces, particularly laterally directed horizontal forces, will cause slippage between the contacting surfaces. The problem is exacerbated when the ends of the corner post are rounded, because rounded ends are susceptible to rolling.
One consequence of not joining the contact areas between opposing walls is a reduction in buckling resistance. For example, a vertical compression force impinging on one wall can cause buckling of that wall while the opposing wall remains stable.
Another disadvantage of not joining contact areas is that it results in a reduction in lateral compression stiffness. For example, when subjected to a lateral compression force, one wall can slip with respect to the opposite wall. Users of packaging supports such as corner posts often require high lateral compression stiffness to prevent their products from being damaged by impacts along the lateral direction.
The present invention overcomes these and other disadvantages by providing an improved corner post in which areas of contact between opposing walls are joined together. The opposing walls may be joined by adhesive, stitching, or any other suitable means. Joining opposing walls along the areas of contact prevents relative movement between the opposing walls which allows the walls to support each other. Joining opposing walls also improves the lateral stiffness of the entire structure.
Thus it is an object of the present invention to provide a support post made from a continuously formed wrap of material which is reformed into a corner or wall post having opposing walls in which areas of contact between the walls are joined together.
Another object of the present invention is to prevent relative movement between the contact surfaces of opposing walls of a tubular corner post so the entire structure is stiffened.
Still another object of the present invention is to provide a support post in which the opposing walls do not quite contact each other but are nevertheless joined together.
Further and additional objects will appear from the description, accompanying drawings, and appended claims.